1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus using an electrophotographic process and to a process cartridge.
Here, the electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium using an electrophotographic image forming process. The electrophotographic image forming apparatus includes, for example, an electrophotographic copying machine, an electrophotographic printer (e.g., a laser beam printer, an LED printer and the like), a facsimile apparatus, a word processor and the like.
In addition, the process cartridge may be a cartridge into which charging means, developing means or cleaning means and an electrophotographic photosensitive member are integrally incorporated, and which is detachably mountable to an image forming apparatus main body. Alternatively, the process cartridge may be a cartridge into which at least one of charging means, developing means and cleaning means and an electrophotographic photosensitive member are integrally incorporated, and which is detachably mountable to an image forming apparatus main body. Further alternatively, the process cartridge may be a cartridge into which at least developing means and an electrophotographic photosensitive member are integrally incorporated, and which is detachably mountable to an image forming apparatus main body.
2. Description of Related Art
Conventionally, in an image forming apparatus using an electrophotographic image forming process, a process cartridge system is employed, which makes an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member integrally into a cartridge which is detachably mountable to an electrophotographic image forming apparatus main body. According to the process cartridge system, since a user can carry out maintenance of an apparatus in person without relying on service personnel, operability can be remarkably improved. Thus, the process cartridge system is widely used in the electrophotographic image forming apparatuses.
Incidentally, in recent years, various kinds of image forming apparatuses have come to be manufactured in a short period of time accompanied with changes in needs in the market.
Therefore, manufacturers cope with the shortened manufacturing cycle by frequently making apparatus parts into a common part. In addition, the manufacturers improve only parts corresponding to a new specification of a new product to further make the parts into a common part and obtain advantages in terms of time and costs.
However, if making the parts into a common part or sharing of parts is advanced as described above, there is less difference between forms of new and old in units such as a process cartridge, which makes the units mountable to new and old image forming apparatus main bodies. In this case, if a new specification of a new image forming apparatus main body includes increase of speed and the like, when an old process cartridge is mounted to the flew image forming apparatus main body, there is a fear that the old process cartridge cannot cope with the speed sufficiently.
It is an object of the present invention to provide an image forming apparatus to which a process cartridge of a different specification is made unmountable if the image forming apparatus cannot cope sufficiently with the specifications of the process cartridge when the process cartridge is mounted.
It is another object of the present invention to provide an image forming apparatus to which a process cartridge of low speed performance is unmountable and a process cartridge of high speed performance is mountable.
It is still another object of the present invention to provide a process cartridge that is mountable to an image forming apparatus of a different specification only if the process cartridge can cope with the specification when it is mounted to the image forming apparatus.
It is a further object of the present invention to provide a process cartridge that is mountable even to an image forming apparatus of lower speed performance.
It is a still further object of the present invention to provide a process cartridge comprising:
an electrophotographic photosensitive drum;
processing means for acting on the electrophotographic photosensitive drum;
a frame for holding the electrophotographic photosensitive drum;
convex portions, which are provided coaxially with an axis of the electrophotographic photosensitive drum and protrude from one side and from the other side of the frame, for positioning the process cartridge in the apparatus main body when the process cartridge is mounted to the electrophotographic image forming apparatus main body; and
a concave portion provided in the upper part of the frame and recessed in the one side, in which the concave portion allows the process cartridge to be inserted into the apparatus main body without abutting against a protrusion provided in the apparatus main body in an inserting process of the process cartridge.
It is another object of the present invention to provide an electrophotographic image forming apparatus comprising:
(a) a protrusion provided on an internal wall surface of the apparatus main body;
(b) mounting means for detachably mounting a process cartridge, wherein the process cartridge includes an electrophotographic photosensitive drum, processing means for acting on the electrophotographic photosensitive drum, a frame for holding the electrophotographic photosensitive drum, convex portions, which are provided coaxially with an axis of the electrophotographic photosensitive drum and which protrude from one side and from the other side of the frame, for positioning the process cartridge in the apparatus main body when the process cartridge is mounted to the apparatus main body and a concave portion provided in the upper part of the frame and recessed in the one side, in which the concave portion allows the process cartridge to be inserted into the image forming apparatus main body without abutting against the protrusion in an inserting process of the process cartridge; and
(c) conveying means for conveying the recording medium.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.